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[Cadence]

From the factory the M3 uses 25.8" front tires and 26.3" rear tires = 0.5" difference front to rear.

I want to use 255/35-19 front and 295/30-19 rear but both are 26" tall = no difference.

Does anyone use these sizes or two other sizes that have the same or almost the same O.D. front and rear?

I know the tires will fit but perhaps this combo will cause ABS or traction control issues?

My second choice would be 265/30-19 front and 285/30-19 rear = 0.4" difference but they are a bit short in O.D. which is bad for ground clearance on a lowered car.


Thanks

[quality_sound]

I've been wanting to do this same thing simple becasue I HATE the look of different sized tires. It will fill up the front wheel well better and may even mean not needing to lower the car.

[Cadence]

Can anyone else chime in? Is there a technical (i.e. computer/ABS/DSC related) reason why this chassis needs a 0.5" tire diameter difference from front to rear? The non-M E9X chassis cars with stagerred wheels and tires have slightly shorter tires on the rear.

225/35-19 = 25.1"
255/30-19 = 25"

It seems that many E9X M3 track guys use the same size all around. No issues

[smmmurf]

Originally Posted by Cadence

Can anyone else chime in? Is there a technical (i.e. computer/ABS/DSC related) reason why this chassis needs a 0.5" tire diameter difference from front to rear? The non-M E9X chassis cars with stagerred wheels and tires have slightly shorter tires on the rear.

225/35-19 = 25.1"
255/30-19 = 25"

It seems that many E9X M3 track guys use the same size all around. No issues

I wouldn't imagine so. DSC/ABS doesn't need to be retuned when going to square snow setups, and as you mentioned, people run square setups on the track.

The only explanation I might be able to give is that 245/45R18 would be too tall and 255/40R18 would be too little of a stagger/too wide for the amount of understeer or rolling resistance the chassis engineers wanted (or the corresponding 245/40R18 and 255/35R18). I really think the car handles well with the stock setup. It probably would have been good as well with 255/275 from the factory.

The E46 even has a larger rolling diameter on the front... 225/45R18 has a greater circumference than 245/40R18!

[1MOREMOD]

i have a 265/30 square set up i use on the street but i like your idea of 255/35 and 295/30 to fill the front well better and avoid lowering.

[Martin_D]

Yes a lot of people go with 255/35/19 and 295/30/19

[Cadence]

Originally Posted by smmmurf

I wouldn't imagine so. DSC/ABS doesn't need to be retuned when going to square snow setups, and as you mentioned, people run square setups on the track.

The only explanation I might be able to give is that 245/45R18 would be too tall and 255/40R18 would be too little of a stagger/too wide for the amount of understeer or rolling resistance the chassis engineers wanted (or the corresponding 245/40R18 and 255/35R18). I really think the car handles well with the stock setup. It probably would have been good as well with 255/275 from the factory.

The E46 even has a larger rolling diameter on the front... 225/45R18 has a greater circumference than 245/40R18!

Good feedback.

FYI, the E46 M3 uses 225/45-18 & 255/40-18

[Cadence]

Originally Posted by Martin_D

Yes a lot of people go with 255/35/19 and 295/30/19

I was trying so hard to find a combo that would allow me to use Bridgstone RE-11 tires. Both 285/30-19 and 295/30-19 are somewhat unusual sizes.

I don't like the 40mm width difference with the 255 295 set. IMO 20mm is good.

IMO, 275/30-19 & 295/30-19 are probably ideal for an aggressive set up but the tire options are limited and these sizes rub unless the wheel widths and offsets are spot on!